1. Field of the Invention
This invention relates to a drilling tool for drilling holes in solid metal, with a base body which contains at least one chip flute, with at least one replaceable cutting insert on the end surface of the base body located in a recess on the end of a chip flute, and with a blade which is preferably formed by two cutting edges which form an obtuse point angle with one another.
2. Background Information
In general usage, such drilling tools are also designated indexable insert drills.
During drilling work with such indexable insert drills, the chips are basically removed from the cutting edges after they have been bent into a curved shape. The curvature of the chip is caused by the different cutting speeds at individual points or areas of the cutting edges. Basically, the chips flow radially inward from the wall of the boring toward the axis of the drilling tool.
Such drilling tools of the prior art are equipped with replaceable cutting inserts, the faces of which carry chip shaping steps. The chip shaping steps on the faces are oriented approximately parallel to the major cutting edges (European Patent No. 0 181 844 B1), even if the chip shaping steps are hump-like structures in the manner of spot-like projections which project from the rake faces (U.S. Pat. No. 4,215,957 A). The chip shaping is conventionally also achieved by placing obstacles in the path of the chip as it is being removed. As a result of these obstacles, the chip is plastically deformed and immediately deflected in a new direction.